This is the third in a series of reports which the PLATO Services Organization is publishing to keep users up to date on curricular developments on the PLATO system. Materials are listed here under 71 general subject matter areas. The report presents first a list of all subject areas and instructional levels in which PLATO lesson development is in progress. Then all materials available for student use are presented by subject area together with the number of instructional hours and the name of a person to contact for information or user data. (CH)